Error message terror! Now what?

Question

When i tried to open my file I got this terrifying error message. After nearly fainting - the file did open -- but now what? This is a hugely important 18 Artbaord/page file of an entire children's book project. Do I copy & paste all pages & layers to a new file? Do I never trust Artboards again & go back to working with each page in it's own file? I don't dare close this down- in case it doesn't open again. Can someone please tell me what that error message means so I can avoid it in the future? Many thanks!

Answer 1

Karen,
Do I copy & paste all pages & layers to a new file?
That is certainly one thing to do. To be on the (even) safer side, you may also save pages/layers/critical parts of the artwork in separate documents.
Are you saving to own harddisk, or to something/somewhere external? If the latter, which is much more unsafe, switch to the former and copy elsewhere afterwards.
Always copy somewhere else, at least on a daily basis, to somewhere as independent and different (including unsyncronized) as possible, such as DVD burning, external harddisk, whatever, so yo have something to fall back on in the many possible terrible events.
Leaving copies behind with different names is also a way of reducing losses.
Basically, the error message tells you that something went wrong in the saving process so the file became corrupt, probably, some code is simply missing.
For an even scarier case where you are unable to open the document, there are still ways to (hopefully) recover all or most:
One thing often tried first is to create a new document and File>Place the corrupted one to see how much may be rescued that way.
Here is a website where you can see whether it can rescue the file, and if it can, you may pay for a subscription to have it done,
http://www.recoverytoolbox.com/buy_illustrator.html
and another similar website,
http://markzware.com/adobe-software/fix-illustrator-file-unknown-error-occurred-pdf2dtp-fi le-recovery/
As far as I remember, the former is for Win and the latter for Mac.
Here are a few pages about struggling with it yourself:
http://daxxter.wordpress.com/2009/04/16/how-to-recover-a-corrupted-illustrator-ai-file/
http://helpx.adobe.com/illustrator/kb/troubleshoot-damaged-illustrator-files.html
http://kb2.adobe.com/cps/500/cpsid_50032.html
http://kb2.adobe.com/cps/500/cpsid_50031.html